Situation based under speed for a predictive cruise control

Abstract

A computer system comprising a processor device configured to: control a prime mover of the first vehicle to operate the first vehicle at a target set speed, determine a rear traffic condition indicating whether there is a risk of being overtaken by a second vehicle travelling behind the first vehicle, determine a topography of an upcoming road to be travelled by the first vehicle, and reduce the target set speed of the first vehicle from a nominal set speed, said nominal set speed being the current speed of the first vehicle, to a reduced set speed, in response to the indicating a descending road condition and the rear traffic condition not indicating a risk of being overtaken by the second vehicle before arriving at the descending road condition.

The invention claimed is: 
     
         1 . A computer system comprising a processor device configured to:
 control a prime mover of the first vehicle to operate the first vehicle at a target set speed,   determine a rear traffic condition indicating whether there is a risk of being overtaken by a second vehicle travelling behind the first vehicle,   determine a topography of an upcoming road to be travelled by the first vehicle, and   reduce the target set speed of the first vehicle from a nominal set speed, said nominal set speed being the current speed of the first vehicle, to a reduced set speed, in response to the topography indicating a descending road condition and the rear traffic condition not indicating a risk of being overtaken by the second vehicle before arriving at the descending road condition.   
     
     
         2 . A computer-implemented method for controlling speed of a first vehicle, the method comprising:
 controlling, by a processor device of a computer system, a prime mover of the first vehicle to operate the first vehicle at a target set speed,   determining, by the processor device, a rear traffic condition indicating whether there is a risk of being overtaken by a second vehicle travelling behind the first vehicle,   determining, by the processor device, a topography of an upcoming road to be travelled by the first vehicle, and   reducing, by the processor device, the target set speed of the first vehicle from a nominal set speed, said nominal set speed being the current speed of the first vehicle, to a reduced set speed, in response to the topography indicating a descending road condition and the rear traffic condition not indicating a risk of being overtaken by the second vehicle before arriving at the descending road condition.   
     
     
         3 . The method of  claim 2 , wherein the step of determining the rear traffic condition comprises:
 obtaining, by the processor device, distance information from a rear distance sensor of the first vehicle, said distance information describing at least a current distance between the first vehicle and the second vehicle, and   processing, by the processor device, the distance information to determine the rear traffic condition based on at least the distance information.   
     
     
         4 . The method of  claim 2 , further comprising:
 increasing, by the processor device, the target set speed of the first vehicle from the reduced set speed to a current road speed limit, in response to the first vehicle not having arrived at the descending road condition and the rear traffic condition indicating a risk of being overtaken by the second vehicle.   
     
     
         5 . The method of  claim 2 , further comprising:
 increasing, by the processor device, the target set speed of the first vehicle from the reduced set speed to the nominal set speed, in response to the first vehicle not having arrived at the descending road condition and the rear traffic condition indicating a risk of being overtaken by the second vehicle.   
     
     
         6 . The method of  claim 2 , wherein the rear traffic condition is determined to indicate a risk of being overtaken by the second vehicle before arriving at the descending road condition in response to a distance between the second vehicle and the first vehicle being below a predetermined rear distance limit. 
     
     
         7 . The method of  claim 6 , wherein the rear distance limit is dynamically adjusted by the processor device in response to a change in road speed limit. 
     
     
         8 . The method of  claim 2 , wherein the rear traffic condition is determined to indicate a risk of being overtaken by the second vehicle before arriving at the descending road condition in response to a speed difference between the first vehicle and the second vehicle exceeding a speed difference limit. 
     
     
         9 . The method of  claim 2 , wherein the reduced set speed is determined by:
 estimating, by the processor device, a speed increase of the first vehicle based on a vertical extent of the descending road condition, wherein a difference between the reduced set speed and the current speed of the first vehicle is proportional to the estimated speed increase of the first vehicle.   
     
     
         10 . A vehicle comprising the processor device to perform the method of  claim 2 . 
     
     
         11 . A computer program product comprising program code for performing, when executed by the processor device, the method of  claim 2 . 
     
     
         12 . A control system comprising one or more control units configured to perform the method of  claim 2 . 
     
     
         13 . A non-transitory computer-readable storage medium comprising instructions, which when executed by the processor device, cause the processor device to perform the method of  claim 2 .